Anther is missing in squash flowers

Asked July 11, 2019, 1:20 AM EDT

Hello, I am growing red kuri winter squash. I grew and harvested one squash and now new flowers are forming. The problem is that all the anthers on male flowers are extremely tiny and no pollen. They were fine previously. Now all males on all vines are like this. Any idea what happened? The plant is otherwise healthy. Thank you!